EP0598990A1 - Vergaser mit Beschleuniger und Leerlaufkreislaufabsperrung - Google Patents
Vergaser mit Beschleuniger und Leerlaufkreislaufabsperrung Download PDFInfo
- Publication number
- EP0598990A1 EP0598990A1 EP93112706A EP93112706A EP0598990A1 EP 0598990 A1 EP0598990 A1 EP 0598990A1 EP 93112706 A EP93112706 A EP 93112706A EP 93112706 A EP93112706 A EP 93112706A EP 0598990 A1 EP0598990 A1 EP 0598990A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- piston
- fuel
- throttle
- valve
- idle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M3/00—Idling devices for carburettors
- F02M3/02—Preventing flow of idling fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M17/00—Carburettors having pertinent characteristics not provided for in, or of interest apart from, the apparatus of preceding main groups F02M1/00 - F02M15/00
- F02M17/02—Floatless carburettors
- F02M17/04—Floatless carburettors having fuel inlet valve controlled by diaphragm
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M7/00—Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
- F02M7/06—Means for enriching charge on sudden air throttle opening, i.e. at acceleration, e.g. storage means in passage way system
- F02M7/08—Means for enriching charge on sudden air throttle opening, i.e. at acceleration, e.g. storage means in passage way system using pumps
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S261/00—Gas and liquid contact apparatus
- Y10S261/68—Diaphragm-controlled inlet valve
Definitions
- This invention relates to engine fuel systems, and more particularly to gasoline carburetors for internal combustion engines.
- Previously known carburetors for small engines have a flexible diaphragm disposed in a fuel chamber which supplies fuel to both main and idling nozzles or orifices opening into a venturi through which combustion air flows when the engine is operating.
- the other side of the diaphragm is subjected to atmospheric pressure and in operation controls a fuel inlet valve disposed between the fuel chamber and a supply of fuel to regulate and maintain substantially constant the pressure of fuel in the fuel chamber.
- a carburetor with idle and main metering jets is supplied with fuel from a common metering chamber in which a combined accelerator pump and shut-off device controls the flow of fuel to the idle jet.
- the accelerator and shut-off device is actuated by movement of the throttle from its idle position to initially supply a relatively small quantity of additional fuel for accelerating the engine and to shut-off the idle circuit under wide open throttle operating conditions. Shutting off the idle circuit prevents bleed back of fuel so that when the throttle returns to its idle position and the shut-off device opens, fuel is immediately supplied to the idle jet for operation of the engine under idle conditions.
- the shut-off device has a combined piston and valve assembly yieldably biased to its retracted and open position when the throttle is in its idle position.
- the piston and valve are operably connected with the throttle shaft so that when it moves the throttle valve to its wide open position it also moves the piston to its advanced position to deliver a small quantity of additional fuel to accelerate the engine and closes the valve to prevent fuel from bleeding from the idle circuit during wide open throttle operating conditions.
- Objects, features and advantages of this invention are to provide a carburetor with fuel supplied to main and idle jets from a common metering chamber which facilitates acceleration of an engine from its idle condition, substantially eliminates momentary hesitation and stumbling of the engine as it rapidly accelerates from its idle condition, eliminates stumbing and stalling of the engine during its rapid transition from wide open throttle to idle operating conditions, decreases carbon monoxide and other engine exhaust emissions, provides a more desirable fuel to air ratio and mixture during engine part throttle operating conditions, is of relatively simple design and economical manufacture and assembly, and has a long useful life in service.
- FIGS. 1 and 2 illustrate a diaphragm carburetor 10 embodying this invention with a body 12 having a through venturi passage 14 in which a throttle valve plate 16 (Fig. 3) mounted on a throttle shaft 18 is disposed.
- the throttle valve is movable from its idle position, as shown in FIG. 3 to a wide open throtle position by rotating the shaft 18 so that the plate 16 is disposed substantially parallel to the direction of flow of air through the venturi.
- a choke valve plate 20 mounted on a choke shaft 22 is also disposed in the venturi passage upstream of the throttle valve.
- the carburetor is mounted on an intake manifold of an engine so atmospheric air will flow through the venturi passage 14 in the direction of the arrow 24.
- Fuel is supplied to both a main metering nozzle 26 and an idle fuel pocket 28 and ports 30, 32, 34 and 36 from a metering chamber 40 in the body.
- fuel in the metering chamber is maintained at a substantially constant subatmospheric pressure by a metering valve 42 actuated by a diaphragm 44 with one face communicating with the metering chamber 40 and the other with the atmosphere.
- the valve 42 is operably connected to the diaphragm by a lever arm 46 pivoted on a pin 48 and biased by a spring 50.
- the quantity of fuel normally supplied to the idle pocket 28 and ports 30-36 from the metering chamber can be varied and adjusted within predetermined limits by a needle valve 52 received in a threaded passage 54 with a seat 56 therein and communicating with the metering chamber through a port 58.
- the quantity of fuel supplied to the main nozzle 26 can be varied and adjusted within predetermined limits by a needle valve 59 threaded in a passage with a complementary seat (not shown) and in communication with the metering chamber and the main jet or nozzle 26. Since the high speed jet, idle well, idle ports, needle valves, metering chamber and diaphragm may be all of conventional construction well-known to those skilled in the art, they will not be described in further detail herein.
- an accelerator pump and shut-off device 60 controls the quantity of fuel supplied to the idling well and ports under various operating conditions.
- the device has a pump chamber 62 formed by a blind bore 64 in the body which receives fuel from the metering chamber 40 through a passage 66 which communicates with the idle adjustment valve 52. Fuel is supplied to the idle well 28 and ports 30-36 through a passage 68 which communicates with the pump chamber 62 and the idle well 28.
- the device has a piston 70 slidably received in the bore 64 and bearing on a guide 72 in which a valve 74 is slidably received.
- the piston and guide are yieldably biased to their retracted positions by a compression spring 76 received in the chamber and the valve 74 is yieldably biased into engagement with the guide by a compression spring 78 received in a pocket 79 in the piston.
- the preload of the spring 78 is less than the preload of the spring 76.
- a seal is provided between the bore 64 and the piston by an O-ring 80 received in a groove 82 in the piston.
- the piston is advanced by a cam 84 in the throttle shaft which bears on a head 86 of the piston.
- the valve 74 has a stem 88 slidably received in a central bore 90 through the annular guide 72 and terminating in a conical tip 92 which when the valve is advanced bears on and seals with a complementary seat 94 in the bore.
- its pocket 79 communicates with the chamber 62 through passages 98 & 100 in the stem.
- the piston 70 does not bottom out on the valve when it is fully advanced by rotation of the cam 84 by the throttle shaft 18. Similarily, to prevent damage to the cam 84 and piston head 86, preferably the guide 72 does not bottom out in the bore 64 when the piston 70 is fully advanced.
- the cam 84 has a generally flat face 102 which bears on the piston when the throttle plate 16 is in the idle position and an edge 104 which bears on the piston as it is moved by the cam.
- the edge 102 has a relatively sharp radius where it blends into the cylindrical peripheral surface of the shaft.
- Reverse flow of fuel through the passage 68 is prevented by a check valve assembly 106 press fit therein and having a disc 108 entrapped in a retainer 110 and receivable on a seat 112 to seal and check or prevent reverse flow of the fuel.
- a check valve assembly 106 press fit therein and having a disc 108 entrapped in a retainer 110 and receivable on a seat 112 to seal and check or prevent reverse flow of the fuel.
- the carburetor is attached to the intake manifold of an engine which is typically a two-stroke or a four-stroke internal combustion engine with an output of 1/4 to 50 horsepower.
- the piston 70 is retracted and the valve 74 is open so that fuel is supplied to th idle well 28 and ports 30-36 through the passages 66 & 68 and the check valve 106.
- the throttle valve plate 16 and shaft 18 are in the closed position, as shown in FIG. 3 of the drawings.
- air flows through the ports 30-34 upstream of the throttle plate entrains fuel in the idle pocket 28 and is discharged through the idle port 36 downstream of the plate and into the intake manifold of the engine.
- the cam 84 advanced the piston 70 and valve 74 so that the valve tip 92 bears on the seat 94 and shuts off the flow of fuel from the entering chamber 62. Further advancement of the piston by rotation of the throttle shaft also pumps a quantity of fuelbfrom the chamber 62 through the idle well 28 and ports 30-36 and into the intake manifold which provides fuel for initially accelerating the engine. As the engine accelerates, the flow of air through the venturi increases and thus fuel is supplied through the high speed or main metering nozzle 26. During wide open throttle operation, the valve 74 remains closed so that no additional fuel is supplied to the idle well. During wide open throttle operation of the engine, the check valve 104 prevents any back-flow of fuel and any entrained air from the idle well toward the chamber 62.
- the cam 84, piston and valve assembly is designed and constructed so that when the throttle is only partially open the valve 74 bears on the seat and shuts off the supply of fuel to the idle well 28 and ports 30-36 thereby eliminating the influence of the idle circuit on the fuel ratio or mixture under engine partial load conditions so that the fuel mixture is determined solely by the main nozzle 26.
- This provides a better fuel to air mixture for operating the engine under partial load conditions and reduces carbon monoxide and other engine exhaust emissions.
- the extent to which the throttle is opened when the valve 74 first closes can be varied by changing the extent and rate of the cam displacement of the piston 70 relative to the extent of the lost motion between the piston and the valve 74.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of The Air-Fuel Ratio Of Carburetors (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/980,462 US5250233A (en) | 1992-11-23 | 1992-11-23 | Carburetor with accelerator and idle circuit shut-off |
US980462 | 1992-11-23 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0598990A1 true EP0598990A1 (de) | 1994-06-01 |
EP0598990B1 EP0598990B1 (de) | 1997-10-15 |
Family
ID=25527571
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP93112706A Expired - Lifetime EP0598990B1 (de) | 1992-11-23 | 1993-08-06 | Vergaser mit Beschleuniger und Leerlaufkreislaufabsperrung |
Country Status (4)
Country | Link |
---|---|
US (1) | US5250233A (de) |
EP (1) | EP0598990B1 (de) |
JP (1) | JP2501079B2 (de) |
DE (1) | DE69314599T2 (de) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1207294A2 (de) * | 2000-11-10 | 2002-05-22 | Walbro Corporation | Vergaser mit Entlüftungssystem |
CN101016869B (zh) * | 2006-02-08 | 2011-06-08 | 安德烈亚斯.斯蒂尔两合公司 | 薄膜化油器 |
Families Citing this family (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3487909B2 (ja) * | 1994-06-20 | 2004-01-19 | 株式会社日本ウォルブロー | 気化器の始動燃料供給装置 |
US5611312A (en) * | 1995-02-07 | 1997-03-18 | Walbro Corporation | Carburetor and method and apparatus for controlling air/fuel ratio of same |
US5843345A (en) * | 1995-12-22 | 1998-12-01 | Briggs & Stratton Corporation | Pneumatic accelerator for low emission charge forming devices |
JP2000220527A (ja) | 1999-02-01 | 2000-08-08 | Nippon Walbro:Kk | 気化器の加速装置 |
US6267102B1 (en) | 2000-02-23 | 2001-07-31 | Walbro Corporation | Carburetor with displaced idle flow |
US6394426B1 (en) * | 2000-07-07 | 2002-05-28 | Walbro Corporation | Engine dual fuel supply apparatus |
US6715737B2 (en) * | 2000-08-29 | 2004-04-06 | Walbro Corporation | Fuel metering system for a carburetor |
US6446939B1 (en) | 2000-08-29 | 2002-09-10 | Walbro Corporation | Modular diaphragm carburetor |
DE10120127B4 (de) * | 2001-04-25 | 2012-07-12 | Andreas Stihl Ag & Co. | Membranvergaser |
DE20107670U1 (de) * | 2001-05-05 | 2002-06-13 | Stihl Maschf Andreas | Vergaseranordnung mit einer Beschleunigerpumpe |
DE10327905A1 (de) * | 2003-06-20 | 2005-01-05 | Andreas Stihl Ag & Co. Kg | Vergaser |
JP2005061289A (ja) * | 2003-08-11 | 2005-03-10 | Zama Japan Kk | 気化器 |
DE10341600A1 (de) * | 2003-09-10 | 2005-04-14 | Andreas Stihl Ag & Co. Kg | Vergaseranordnung eines handgeführten Arbeitsgerätes |
US7165536B2 (en) * | 2004-06-14 | 2007-01-23 | Tecumseh Products Company | Evaporative emissions control system for small internal combustion engines |
CN2799874Y (zh) * | 2005-04-22 | 2006-07-26 | 陈献祥 | 蝶阀式移动喷口立体膜片化油器 |
JP2008215153A (ja) | 2007-03-02 | 2008-09-18 | Walbro Japan Inc | 気化器の加速装置 |
US20080302332A1 (en) * | 2007-06-05 | 2008-12-11 | Walbro Engine Management, L.L.C. | Split-bore stratified charge carburetor |
US20130087935A1 (en) * | 2011-10-10 | 2013-04-11 | Walbro Engine Management, L.L.C. | Carburetor shut-off valve |
US9279390B2 (en) | 2013-04-15 | 2016-03-08 | Walbro Engine Management, L.L.C. | Accelerator device for a carburetor |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2261794A (en) * | 1938-10-28 | 1941-11-04 | Carter Carburetor Corp | Carburetor |
US2649290A (en) * | 1946-02-15 | 1953-08-18 | Solex Soc | Carburetor |
US2679835A (en) * | 1949-06-28 | 1954-06-01 | Robert H Thorner | Carburetor |
US3003754A (en) * | 1958-12-16 | 1961-10-10 | Tillotson Mfg Co | Charge forming apparatus |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2824725A (en) * | 1958-02-25 | Carburetor | ||
US3743254A (en) * | 1970-12-10 | 1973-07-03 | Walbro Corp | Diaphragm carburetor |
DE3715272C1 (de) * | 1987-05-08 | 1988-06-30 | Stihl Maschf Andreas | Membranvergaser |
-
1992
- 1992-11-23 US US07/980,462 patent/US5250233A/en not_active Expired - Lifetime
-
1993
- 1993-08-06 EP EP93112706A patent/EP0598990B1/de not_active Expired - Lifetime
- 1993-08-06 DE DE69314599T patent/DE69314599T2/de not_active Expired - Fee Related
- 1993-08-30 JP JP5214407A patent/JP2501079B2/ja not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2261794A (en) * | 1938-10-28 | 1941-11-04 | Carter Carburetor Corp | Carburetor |
US2649290A (en) * | 1946-02-15 | 1953-08-18 | Solex Soc | Carburetor |
US2679835A (en) * | 1949-06-28 | 1954-06-01 | Robert H Thorner | Carburetor |
US3003754A (en) * | 1958-12-16 | 1961-10-10 | Tillotson Mfg Co | Charge forming apparatus |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1207294A2 (de) * | 2000-11-10 | 2002-05-22 | Walbro Corporation | Vergaser mit Entlüftungssystem |
EP1207294A3 (de) * | 2000-11-10 | 2003-06-18 | Walbro Corporation | Vergaser mit Entlüftungssystem |
CN101016869B (zh) * | 2006-02-08 | 2011-06-08 | 安德烈亚斯.斯蒂尔两合公司 | 薄膜化油器 |
DE102006005696B4 (de) * | 2006-02-08 | 2016-02-11 | Andreas Stihl Ag & Co. Kg | Membranvergaser |
Also Published As
Publication number | Publication date |
---|---|
JP2501079B2 (ja) | 1996-05-29 |
DE69314599D1 (de) | 1997-11-20 |
US5250233A (en) | 1993-10-05 |
JPH06167248A (ja) | 1994-06-14 |
EP0598990B1 (de) | 1997-10-15 |
DE69314599T2 (de) | 1998-02-19 |
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